There seems to be quite a few of these errors both on the ngccoin site and in the SCWC.
And to be honest, I don't think they're accidental. I think it's to protect their "intellectual property".
The reason why I say this is that I saw a documentary a while ago about the "A to Z" versions of street maps. Not sure if "A to Z" is global, but in the UK they produce street level maps of all towns and cities in the UK. (Pre Google Maps of course)
In the documentary they said that every single map they produce they add several mistakes, whether it's a road that shouldn't be there, a spelling mistake of a street name, etc, but they don't tell anyone where the mistakes are.
This means that if anyone copies their maps verbatim, with no checking, these errors will also be copied, and the owners of "A to Z" know that that particilar map is a copy of theirs.
Could this be the same thing?
http://www.facebook.com/NumismaticsUK
I'm not an expert in any kind of coins, but I reckon I'm good at research and will do my best to help. Feel free to tell me my identifications/valuations/gradings are wrong. It's the only way I'll learn.
It's a technique dating back from the "cold war" feeding different errors into documents to find the "moles" in the intelligence services. Now it's probably also used in industrial spying.
